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User blog:Adeblanc/Kinds of Elements
Writers often describe some elements as "artifical" or "synthetic". That's wrong for two reasons. First, polar jets which are part of stars, neutron stars, and black holes function as really big, really sloppy particle accelerators. They are, in fact, colliders. Particles with the same charge will all appear to rotate in the same direction when viewed along their axis of travel. In polar jets, particles don't stay in phase, which means they will collide with each other from time to time. Anything physicists can do in the lab with finely tuned, picoampere beams of isotopically pure ions; nature can do with thousand-ampere currents of anything that happens to be present, particularly since beam times of centuries are possible. Considering that there are literally billions of such jets out there, even the least likely of events will occur somewhere. Second, physicists are natural phenomena. The Milky Way alone is estimated to contain up to 200 billion planets, of which at least 1% are both terrestrial and orbiting in their star's habitable zone. We know that procaryotic life began on earth over 3. billion years ago and that eucaryotic life (our kind) began 1 billion years ago. We also know that life can adapt to environments that would kill a human in seconds. Finally, we know there are billions and billions of galaxies out there. Can something truly be called "artificial" when the physicists making it live on a planet in the Andromeda galaxy? It is more meaningful to group elements by the part they play in the universe. Elements with Z bertween 1 (H) and 100 (Fm) inclusive might be called "terrestrial elements". All are present in today's earth, although fermium is something of an honorary member of the set. Spontaneous fission of U238 does create fermium, but only in parts-per-planet quantity. Since heavy fermium isotopes fission instead of beta-decaying to form mendelevium, the set ends at Z=100. Terrestrial elements are a part of everything. Elements with Z between 106 (Sg) and 114 (Fl) and some with Z in the range 122 to 130 might be called "astronomical elements". It appears likely that they will form in quantity by rapid neutron capture or fission infall, and will persist for decades after they form. These elements are part of very young astronomical objects, such as supernova or kilonova remnants. They will be rare, granted, probably too rare to detect with forseeable technology - but they will be present. All the others might be called "transient elements". Some, such as those with Z between 101 (Md) and 105 (Db) should form by neutron capture in supernovae and neutron star mergers (kilonovae). Others may form by fission infall from really big nuclides dredged up from deep within disintegrating neutron stars. Still others can form only in polar jets. None of them, however, will persist long enough to outlive the event which created them. The distinction matters because neither the physics of nuclei nor chemistry of atoms are abstractions. They are the stuff of which most of the observable universe is made. (Neutron stars consist largely of nuclear matter rather than isolated atomic nuclei, and what's inside black holes can never be truly known.) Grouping elements into terrestrial, astronomical, and transient clarifies what part of reality a given element belongs in. Category:Blog posts